The objective of this research is the continued participation in the Epidemiologic Catchment Area (ECA) Program by Duke University Medical Center. The ECA Program is a multi-site research program sponsored by the National Institute of Mental Health. Duke University has participated in the ECA program since 1/1/1981. The planned research is divided into four components. The first component, data analysis, involves the indepth analysis of with-in site and cross-site data collected at three points in time during the first phase of the ECA program. Duke has lead-site responsibility for the cross-site analysis of somatization disorder, multivariate models of health service utilization, and urban/rural comparisons. The with-in site topics for analysis include stress, social support, and psychiatric disorder; relating respondent data to medical record data; premenstrual syndrome, psychotropic drug use; mathematical models of nosology and disease classification; and statistical techniques for estimating prevalence and incidence. The second component, the elderly followback study, will collect data at three points in time from respondents aged 60 and older in order to determine the course of mental illness in late life, examine the onset of psychiatric disorder in late life, and monitor cognitive decline over time. A mortality followup of all respondents will focus on psychiatric disorder as a mortality risk factor. The third component will collect data on the characteristics of the health services delivery system. The data will be merged with respondent data to examine system effects on levels of use, amount of unmet need, and help-seeking outside the area. The final component is a test-retest reliability study of the Diagnostic Interview Schedule (DIS).